Air pump



@du @y E934. E. H SMH-H llg AIR PUMP Filed July 27 1933 h i-N /8 /3 25 lzz as MEE' /1 JM/ TH Patented Oct. 9, 1934 UNITED STATES PATENT OFFICEAm PUMP Application July 27, 1933, Serial No. 682,456

3 Claims.

This invention relates to new and useful improvements in air compressorpumps and has as an object to provide such a pump of simple andinexpensive construction, and which requires no lubrication.

A further object is to provide an air pump comprising a body having adiaphragm secured thereto and cooperating with a wall thereof to providea chamber, and said chamber having air inlet and outlet openingsprovided with check valves, each of which comprises a relativelylight-weight valve diskmounted for limited movement within theirrespective openings and operating to control the directional ow of theair through the pump,

when the diaphragm is operated.

Other objects of the invention reside in the simple and inexpensiveconstruction of the pump, as a whole, including the air inlet and outletvalves; in the novel manner of securing the diaphragm to its operatingmember whereby there is no relative movement between said parts; in theparticular arrangement of the diaphragm and its operating means, wherebythe central portion of the diaphragm is operated symmetrically about themedial plane thereof, lto thereby relieve it of unnecessary strains; andin the means embodied in the construction of the intake valve to permita slight leakage of air through said valve, when the diaphragm is idlingat a relatively lower speed than normal, to thereby relieve theapparatus of an unnecessary load.

Other objects of the invention will appear from the followingdescription and accompanying drawing and will be pointed out in theannexed 85 claims.

In the accompanying drawing, there has been disclosed a structuredesigned to carry out the various objects of the invention, but it is tobe understood that the invention ls not confined to the exact featuresshown as various changes may be made Within the scope of the claimswhich follow.

In the drawing:

Figure 1 is an elevational view, partially in section, showing the novelpump operatively connected to a motor;

Figure 2 is an .enlarged detail sectional view showing theinterioiconstruction of the pump; and

Figure 3 is an enlarged detail sectional view more clearly showing theconstruction of the seat of the intake valve.

In the selected embodiment of the invention here shown, for purposes ofdisclosure, there is illustrated'in Figure 1, a base member 2 having a(Cl. 23o-170) motor 3 suitably secured thereto. A standard 4 is shownmounted at one end of the base and terminates at its upper end in anannular frame or annulus 5, having a central opening 6 therein.

An important feature of this invention resides in the construction ofthe air compressor or pump supported upon the annular frame 5 of thestandard 4. This pump comprises a body 7 which forms a housing for aplurality of valves which will subsequently be described. The housing 7is secured to the annular frame 5 by suitable bolts 8. A diaphragm 9 isclamped between the body portion 7 and the annulus 5 in leakproofrelation. The lower face of the body 7 is concaved, as shown, and thediaphragm 9 Coop- 70 erates therewith to provide a chamber 11.

Air inlet and outlet valves, generally indicated by the numerals 12 and13, respectively, are provided in the body 7. The inlet valve comprisesa plug 14 received in threaded engagement with a 75 socket 15 in thehousing 7. The plug 14 has an aperture 16 extending therethrough whichpreferably is threaded as shown, whereby a pipe or other fitting, notshown, may be connected thereto, if desired. 'I'he lower end of the plug14 ter- 80 minates in an annular flange 17 adapted to be engaged by asmall, semi-flexible disk 18, normally seated upon a raised portion 19provided on the bottom wall 21 of the socket 15. The bottom face 20 ofthe annular flange 17 isrounded, as 8 shown in Figure 3, so as topresent a relatively small surface to the valve disk 18, when the latterengages it under light pressure, as when the diaphragm is idling at arelatively slow speed under no load, thus relieving the apparatus of 9an unnecessary load, when idling. When the motor attains its normalspeed, the valve disk 18 will bethrust against the rounded seat 20 withsufficient force to cause the seat to become slightly depressed in thedisk 18, as indicated by the dotted lines in Figure 3, whereby leakageis positively prevented through the valve 12, when the apparatus isoperating at normal speed. Suitable passages 22 are provided in thebottom wall 21, as shown, to permit free air circulation therethrough.The lower edge of the flange 17 is adapted to be engaged by the disk 18to prevent the compressed air from discharging through said valve fromthe chamber 11, when the diaphragm 9 is actuated. In other Words, thedisk 105 `18 and flange 17 cooperate to -provide a check valve forpermitting air ow through the valve 12 in one direction only.

The outlet valve 13 comprises a solid plug 23 received in threadedengagement with a rocket 24 which is provided at its lower portion withan annular seat 25, adapted to receive a disk valve 26. The bottom ofthe socket 24 communicates with the chamber 11 through a suitableopening 27. A reduced extension 28 depends from the lower portion of theplug 23 and has its lower end terminating in spaced relation to the disk26, thereby to provide means for limiting the movement of said disk. Anoutlet port 29 connects the socket 24 with a pipe 31, received inthreaded engagement with the valve body 7, as clearly illustrated in thedrawing. This pipe 31 may lead to a suitable air storage tank or otherreceiving means.

The means for operating the diaphragm 9 is shown consisting of aconnecting rod 32 having its upper end immovably secured to thediaphragm. A flanged head 33 is adjustably secured to the upper end ofthe connecting rod 32 by suitable threads 34 and an adjusting nut 35. Adish-shaped member 36 is seated upon the flanged head 33, and isdirectly engaged with the central portion of the diaphragm 9, as bestshown in Figure 2. A clamping plate 37 is engaged with the upper face ofthe diaphragm 9 and is secured to the head 33 by suitable bolts 38,whereby the central portion of the diaphragm will be rigidly clampedbetween the inverted dishlike member 36 and the clamping plate 37.

The lower end of the connecting rod has a bearing 39 secured theretowhich is engaged with a crank pin 41 suitably secured to the shaft 42 ofthe motor, as will readily be understood by reference to Figure 1. Thus,when the motor is operated, reciprocal movement will beimparted to theconnecting rod 32 to thereby actuate the diaphragm. The inverteddish-shaped member 36 below the diaphragm provides a support for thelatter when the diaphragm is moved upwardly to discharge the air fromthe chamber 11 through the pipe 31. The diaphragm is of the doubleacting type, that is, it operates to circulate the air on both its upand down stroke. When the diaphragm is moved downwardly, air is drawnthrough the inlet valve 12 which will be open as shown in Figure 2,while the disk 26 of the outlet valve will be closed. Upon the up strokeof the connecting valve, the valve 18 of the inlet valve 12 will engagethe seat 17 and interrupt air flow therethrough while the disk 26 of theair outlet valve 13 will move upwardly into engagement with the terminalof the extension 28 of the plug 23, to thereby permit the air to exhaustfrom the chamber 11 through the outlet valve 13 and into the pipe 31.

An important feature of the invention resides in the specificconstruction of the air inlet and outlet valves 12 and 13. The disks 18and 26 of these valves are preferably made of rubber and are very light,whereby the pump is very sensitive in operation and will function withthe slightest air pressure. The upper end of the connecting rod beingconnected in fixed relation to the diaphragm, eliminates wearingsurfaces and because of the unique construction of the air inlet andoutlet valves, the air pump may be operated indenitely without alubricant, whereby the air discharging from the pipe 31 will always befree from oil and other foreign matter, assuming, of course, that theair drawn through the air inlet valve 12 is free from such matter.

The novel air pump or compressor herein disclosed, has been found veryuseful in connection with beverage dispensing apparatus of the typeemploying air pressure. In such apparatus, it is of utmost importancethat the air pressure contained on top of the liquid or beverage in thebarrel or keg, is maintained substantially constant. Because of thesensitiveness of the pump, it readily lends itself for use in connectionwith such apparatus, and when used in connection with an ordinarypressure regulating device, a constant predetermined pressure may bemaintained in the barrel at all times, regardless of the level of thebeverage therein.

'I'he pump is very simple and inexpensive in construction and comprisesno wearing surfaces and therefore requires no lubrication. The onlymovable parts are the valve disks 18 and 26 and the diaphragm 9, andthese parts may readily be replaced when necessary. By removing theplugs 14 and 23 of the air inlet and outlet valves, respectively, accessmay be had to the disks 18 and 26 and, in like manner, by the removal ofthe valve body 7 from the annulus 5, access may be had to the diaphragm9.

By mounting the valve body 7 upon the standard 4 and operativelyconnecting the diaphragm to the motor 3, as hereinbefore described, theentire apparatus may be constructed as a unit, as shown in Figure 1,whereby it may readily be moved about from place to place withoutinterfering with the operation of the mechanism. The pump is alsosubstantially noiseless in operation, which is a very desirable featurein apparatus of this type.

I claim as my invention:

1. In an air pump, a body having a concaved face, an annular seat insaid face, a diaphragm fitting in said seat, an annulus engaging themarginal edge of the diaphragm and suitably secured to said body tothereby secure the dlaphragm thereto in leak-proof relation, saiddiaphragm being spaced from the concaved face of said body andcooperating therewith to provide a chamber, means for operating thediaphragm, said body having an air inlet opening communicating with saidchamber, said opening having a perforated bottom provided at its centerwith a raised portion, a valve disk supported on said raised portion, aperforated plug received in threaded engagement with the walls of saidopening and having its lower edge normally spaced from said valve disk,said body also having an air outlet opening provided at its bottom withan annular shoulder, avalve disk normally supported on said shoulder, animperforate plug secured in said air outlet opening and having adepending portion normally spaced from said valve, and an air conduitconnected to said air outlet opening between its respective valve diskand said plug, said disks operating as check valves to cause the air tocirculate through said air chamber in one direction, when the diaphragmis actuated.

2. In an apparatus of the class described, a 135 motor, a standardpositioned adjacent thereto and terminating at its upper end in aring-like portion open at its top and bottom, a diaphragm seated on saidring-like portion and having one f ace exposed to the atmosphere, avalve body engaged with said diaphragm, means securing the valve body tothe ring-like portion whereby the diaphragm is secured thereto inleak-proof relation, a connecting rod having one end immovably securedto the diaphragm and having its opposite end connected to a crank pinsecured to the motor shaft, said valve body having the central portionof its bottom face spaced from the diaphragm to provide a chamber, saidchamber having an air outlet and air inlet and outlet valvescommuncating with said chamber, and adapted to be actuated by operationof the diaphragm to thereby cause air to be drawn into said chamber anddischarged therefrom, under pressure, into said air outlet.

3. In an air pump, a body having a concaved face provided' with anannular seat, a diaphragm tting in said seat and secured thereto inleakproof relation, said diaphragm being spaced from the concaved faceof said body and cooperating therewith to provide a chamber, means foroperating the diaphragm, said body having an air inlet openingcommunicating with said chamber, said opening having a perforated bottomprovided with a raised central portion, a valve disk normally supportedon said raised portion, a valve seat secured in said opening and spacedfrom said valve disk and providing means for limiting movement of thedisk, said chamber having an air outlet comprising a threaded recessprovided at its bottom with an annular seat. a valve disk normallysupported on said seat, a plug received-in threaded engagement with saidrecess and having a reduced central portion normally spaced from thevalve disk in said recess and forming an abutment to limit movement ofsaid disk, and an air outlet connected with said recess, said disksoperating as check valves to cause air to circulate through said chamberand into said air outlet, when the diaphragm is actuated.

EIMER H. SMITH.

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